Extra-pair paternity in a population of Chilean Swallows breeding at 54 degrees south

FERRETTI VALENTINA; LILJESTHROM, MARCELA; LOPEZ, ALDANA S.; LOVETTE, IRBY J.; WINKLER, DAVID W.

JOURNAL OF FIELD ORNITHOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 87 p. 155 - 161

0273-8570

<!-- /* Font Definitions */@font-face{font-family:"Arial Unicode MS";panose-1:2 11 6 4 2 2 2 2 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-134238209 -371195905 63 0 4129279 0;} /* Style Definitions */p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-parent:"";margin:0in;margin-bottom:.0001pt;mso-pagination:widow-orphan;font-size:12.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Arial Unicode MS";border:none;}span.MsoPageNumber{mso-style-unhide:no;mso-style-parent:"";mso-ansi-language:EN-US;}span.Hyperlink0{mso-style-name:"Hyperlink.0";mso-style-unhide:no;mso-style-parent:"Page Number";mso-ansi-language:EN-US;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-family:Cambria;mso-ascii-font-family:Cambria;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:"ＭＳ 明朝";mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:Cambria;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}@page WordSection1{size:8.5in 11.0in;margin:1.0in 1.25in 1.0in 1.25in;mso-header-margin:.5in;mso-footer-margin:.5in;mso-paper-source:0;}div.WordSection1{page:WordSection1;}-->Geographic patterns of variation in life-history traits have puzzled researchers for decades. However, the widely accepted idea that mating systems exhibit a tropical-temperate latitudinal trend, with extra-pair mating systems being the norm among temperate species and genetic monogamy the norm among tropical species, is supported by sparse data, particularly for birds breeding in the tropics and even more so for birds that breed in the southern hemisphere temperate zone. Our objective was to examine the genetic mating system of Chilean Swallows (Tachycineta meyeni) breeding at 54°S in Tierra del Fuego, Argentina. From 2006 to 2009, we examined the paternity of young in 52 broods. Contrary to predictions based on their congeners that breed at equivalent latitudes in the northern hemisphere,Chilean Swallows in our study had low rates of extra-pair paternity, with 13.5%of nests (N = 52) having at least one extra-pair young and 6.8% of all nestlings (N= 161) fathered by extra-pair males. These rates are also lower than those reported for species of Tachycineta swallows that breed at tropical latitudes. We found no support for a tropical-south temperate latitudinal cline in extra-pair paternity rates. The highly unpredictable weather of the island of Tierra del Fuego might be influencing parental investment at this site: small clutch sizes and low extra-pair paternity rates are expected if biparental attention is crucial for chick survival and reproductive success for these aerial insectivores. We argue that the sparse sampling of mating systems in birds worldwide may have contributed to a misapprehension of a global pattern. More studies should focus on tropical and south-temperate systems to build on theories based on a wider set of taxa.